MICROMACHINED MONOLITHIC 6-AXIS INERTIAL SENSOR

Description

TECHNICAL FIELD

[0001] The present invention relates generally to inertial sensor devices and more particularly to micromachined inertial sensor devices.

BACKGROUND

[0002] 6-axis motion sensing applications require x, y, and z-axis accelerometers and gyroscopes for 3-axis acceleration and 3-axis angular rate measurement. Several single or multi-axis micromachined accelerometer and gyroscope structures have been reported in the literature that can be integrated into a system to form a 6-axis inertial sensor cluster. However, the size and cost of such clusters consisting of separate sensors can be excessive for certain applications. Further, existing instances of single or multi-axis gyroscopes and accelerometers fabricated on a single micro-electro-mechanical system (MEMS) chip require separate drive and sense electronics for each sensor, further increasing cost and complexity of the resulting single MEMS chip.

[0003] United States Patent Application Publication No.: US 2009/0064780 A1 discloses a driving mass of an integrated microelectromechanical structure that is moved with a rotary motion about an axis of rotation, and a sensing mass that is connected to the driving mass via elastic supporting elements so as to perform a detection movement in the presence of an external stress. The driving mass is anchored to a first anchorage arranged along the axis of rotation by first elastic anchorage elements. The driving mass is also coupled to a pair of further anchorages positioned externally thereof and coupled to opposite sides with respect to the first anchorage by further elastic anchorage elements. The elastic supporting elements and the first and further elastic anchorage elements render the driving mass fixed to the first sensing mass in the rotary motion, and substantially decoupled from the sensing mass in the detection movement, the detection movement being a rotation about an axis lying in a plane.

[0004] United States Patent Application Publication No.: US 2009/0114016 A1 discloses a sensor that measures angular velocity about an axis that is normal to a sensing plane of the sensor. The sensor comprises a sensing subassembly that includes a planar frame parallel to the sensing plane, a first proof mass disposed in the sensing plane, a second proof mass disposed in the sensing plane laterally to the first proof mass, and a linkage within the frame and connected to the frame. The linkage is connected to the first proof mass and to the second proof mass. The sensor further includes an actuator for driving the first proof mass and the second proof mass into oscillation along a drive axis in the sensing plane. The sensor further includes a first transducer to sense motion of the frame in response to a Coriolis force acting on the oscillating first proof mass and the oscillating second proof mass.

OVERVIEW

[0005] The present invention is defined in the independent claims.

[0006] This document discusses, among other things, a 6-degrees-of-freedom (6-DOF) inertial measurement system that may include a single proof-mass 6-axis inertial sensor formed in an x-y plane of a device layer. The single proof-mass 6-axis inertial sensor can include a main proof-mass section suspended about a single, central anchor, the main proof-mass section including a radial portion extending outward towards the edge of the 6-axis inertial sensor, a central suspension system configured to suspend the 6-axis inertial sensor from the single, central anchor, and a drive electrode including a moving portion and a stationary portion, the moving portion coupled to the radial portion, wherein the drive electrode and the central suspension system are configured to oscillate the 6-axis inertial sensor about a z-axis normal to the x-y plane.

[0007] In an example, the 6-DOF inertial measurement system can include a cap wafer bonded to a first surface of the device layer and a via wafer bonded to a second surface of the device layer. In certain examples, the cap wafer and the via wafer can be configured to encapsulate the single proof-mass 6-axis inertial sensor.

[0008] This overview is intended to provide an overview of subject matter of the present patent application. It is not intended to provide an exclusive or exhaustive explanation of the invention. The detailed description is included to provide further information about the present patent application.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In the drawings, which are not necessarily drawn to scale, like numerals may describe similar components in different views. Like numerals having different letter suffixes may represent different instances of similar components. The drawings illustrate generally, by way of example, but not by way of limitation, various comparative examples discussed in the present document.

FIG. 1 illustrates generally a schematic cross sectional view of a 6-degrees-of-freedom (6-DOF) inertial measurement unit (IMU).

FIG. 2 illustrates generally an example of a 6-axis inertial sensor.

FIG. 3 illustrates generally an example of a 6-axis inertial sensor in drive motion.

FIG. 4 illustrates generally an example of a 6-axis inertial sensor including a single proof-mass during sense motion in response to rotation about the x-axis.

FIG. 5 illustrates generally an example of a 6-axis inertial sensor including a single proof-mass during sense motion in response to rotation about the y-axis.

FIG. 6 illustrates generally an example of a 6-axis inertial sensor including a single proof-mass during sense motion in response to rotation about the z-axis.

FIG. 7 illustrates generally an example of a 6-axis inertial sensor including a single proof-mass during sense motion in response to acceleration about the x-axis.

FIG. 8 illustrates generally an example of a 6-axis inertial sensor including a single proof-mass during sense motion in response to acceleration about the y-axis.

FIG. 9 illustrates generally an example of a 6-axis inertial sensor including a single proof-mass during sense motion in response to acceleration about the z-axis.

FIG. 10 illustrates generally an example of a system including via wafer electrode placement.

FIG. 11 illustrates generally an example of a 6-axis inertial sensor including curved in-plane parallel-plate sense electrodes.

FIG. 12 illustrates generally an example of the central suspension at rest about an anchor.

FIG. 13 illustrates generally an example of a portion of the central suspension in drive motion.

DETAILED DESCRIPTION

[0010] The present inventor has recognized, among other things, a micromachined monolithic 6-axis inertial sensor configured to utilize a single center-anchored proof-mass to detect 3-axis acceleration and 3-axis angular rate. Further, the present inventor has recognized a micromachined monolithic 6-axis inertial sensor configured to decouple the response modes for each axis to minimize cross-axis interference.

[0011] In an example, the micromachined monolithic 6-axis inertial sensor can include a partitioned proof-mass and flexure bearing structure configured to allow 3-axis angular rate detection utilizing a single drive-mode oscillation requiring one drive control loop for all axes. Thus, in contrast to existing multi-axis gyroscopes that utilize three separate drive control loops, the complexity and cost of control electronics for the micromachined monolithic 6-axis inertial sensor described herein are significantly reduced. In an example, the flexure bearing structure can provide distinct motion modes for acceleration and angular rate responses, allowing simultaneous accelerometer and gyroscope functionality (e.g., angular rate and linear acceleration detection) from a single proof-mass inertial sensor.

Device Structure

[0012] FIG. 1 illustrates generally a schematic cross sectional view of a 6-degrees-of-freedom (6-DOF) inertial measurement unit (IMU) 100 formed in a chip-scale package including a cap wafer 101, a device layer 105 including micromachined structures (e.g., a micromachined monolithic 6-axis inertial sensor), and a via wafer 103. In an example, the device layer 105 can be sandwiched between the cap wafer 101 and the via wafer 103, and the cavity between the device layer 105 and the cap wafer 101 can be sealed under vacuum at the wafer level.

[0013] In an example, the cap wafer 101 can be bonded to the device layer 105, such as using a metal bond 102. The metal bond 102 can include a fusion bond, such as a non-high temperature fusion bond, to allow getter to maintain long term vacuum and application of anti-stiction coating to prevent stiction that can occur to low-g acceleration sensors. In an example, during operation of the 6-DOF IMU 100, the metal bond 102 can generate thermal stress between the cap wafer 101 and the device layer 105. In certain examples, one or more features can be added to the device layer 105 to isolate the micromachined structures in the device layer 105 from thermal stress, such as one or more stress reducing grooves formed around the perimeter of the micromachined structures. In an example, the via wafer 103 can be bonded to the device layer 105, such as fusion bonded (e.g., silicon-silicon fusion bonded, etc.), to obviate thermal stress between the via wafer 103 and the device layer 105.

[0014] In an example, the via wafer 103 can include one or more isolated regions, such as a first isolated region 107, isolated from one or more other regions of the via wafer 103, for example, using one or more through-silicon-vias (TSVs), such as a first TSV 108 insulated from the via wafer 103 using a dielectric material 109. In certain examples, the one or more isolated regions can be utilized as electrodes to sense or actuate out-of-plane operation modes of the 6-axis inertial sensor, and the one or more TSVs can be configured to provide electrical connections from the device layer 105 outside of the 6-DOF IMU 100. Further, the 6-DOF IMU 100 can include one or more contacts, such as a first contact 110, selectively isolated from one or more portions of the via wafer 103 using a dielectric layer 104 and configured to provide an electrical connection between one or more of the isolated regions or TSVs of the via wafer 103 to one or more external components, such as an ASIC wafer, using bumps, wire bonds, or one or more other electrical connection.

[0015] In certain examples, the micromachined monolithic 6-axis inertial sensor in the device layer 105 can be supported or anchored to the via wafer 103 by bonding the device layer 105 to a protruding portion of the via wafer 103, such as an anchor 106. In an example, the anchor 106 can be located substantially at the center of the via wafer 103, and the device layer 105 can be fusion bonded to the anchor 106, such as to eliminate problems associated with metal fatigue.

[0016] FIG. 2 illustrates generally an example of a 6-axis inertial sensor 200 (e.g., a micromachined monolithic 6-axis inertial sensor), such as formed in a single plane of a device layer 105 of a 6-DOF IMU 100. In an example, the structure of the 6-axis inertial sensor 200 can be symmetrical about the x and y axes illustrated in FIG. 2, with a z-axis conceptually coming out of the figure. Reference in FIG. 2 is made to structure and features in one portion of the 6-axis inertial sensor 200. However, in certain examples, such reference and description can apply to unlabeled like portions of the 6-axis sensor 200.

[0017] In an example, the 6-axis inertial sensor 200 can include a single proof-mass design providing 3-axis gyroscope and 3-axis accelerometer operational modes patterned into the device layer 105 of the 6-DOF IMU 100, such as illustrated in the example of FIG. 1.

[0018] In an example, the single proof-mass can be suspended at its center using a single central anchor (e.g., anchor 106) and a central suspension 111 including
symmetrical central flexure bearings ("flexures"). The central suspension 111 can allow the single proof-mass to oscillate torsionally about the x, y, and z axes, providing three gyroscope operational modes, including:

(1) Torsional in-plane drive motion about the z-axis (e.g., as illustrated in FIG. 3);

(2) Torsional out-of-plane y-axis gyroscope sense motion about the x-axis (e.g., as illustrated in FIG. 4); and

(3) Torsional out-of-plane x-axis gyroscope sense motion about the y-axis (e.g., as illustrated in FIG. 5).

[0019] Further, the single proof-mass design can be composed of multiple sections, including, for example, a main proof-mass section 115, x-axis proof-mass sections 116, 117 symmetrical about the y-axis, and y-axis proof-mass sections 118, 119 symmetrical about the x-axis.

[0020] In the example of FIG. 2, the main proof-mass section 115 includes a first bulk portion including the central suspension 111 with main arms extending radially from the center of the main proof-mass section 115 towards respective drive electrodes 123 positioned at the corners of the 6-axis inertial sensor 200. In an example, a combination of the central suspension 111 and the drive electrodes 123 can be configured to provide a torsional in-plane drive motion about the z-axis, allowing detection of angular motion about the x and y axes.

[0021] In an example, the x-axis proof-mass sections 116, 117 can be coupled to the main proof-mass section 115 using multi-function flexure bearings 120, and to each other using z-axis gyroscope anti-phase flexure bearings 121. In an example, the multi-function flexure bearings 120 can allow the x-axis proof-mass sections 116, 117 to oscillate in the following manners:

(1) Linear anti-phase in x-direction for z-axis gyroscope sense motion (e.g., as illustrated in FIG. 6);

(2) Linear in-phase in x-direction for x-axis accelerometer sense motion (e.g., as illustrated in FIG. 7); and

(3) Torsional out-of-plane about the y-axis for the z-axis accelerometer sense motion (e.g., as illustrated in FIG. 9).

[0022] In an example, the anti-phase flexure bearings 121 define a zigzag pattern. In an example, the y-axis proof-mass sections 118, 119 can be coupled to the main proof-mass section 115 using y-axis flexure bearings 122, which can allow the y-axis proof-mass sections 118, 119 to oscillate linear in-phase in y-direction for x-axis accelerometer sense motion.

[0023] Further, the 6-axis inertial sensor 200 can include x-axis accelerometer sense electrodes 125 and z-axis gyroscope sense electrodes 127, 129 configured to detect, respectively, in-phase and anti-phase, in-plane motion of one or more proof-mass sections along the x-axis. In certain examples, the x-axis accelerometer sense electrodes 125 and the z-axis gyroscope sense electrodes 127, 129 can be combined into a single set of sense electrodes. In an example, y-axis accelerometer sense electrodes 131 are configured to detect in-phase, in-plane motion of one or more proof-mass sections along the y-axis.

[0024] In an example, each of the drive electrodes 123, x-axis accelerometer sense electrodes 125, z-axis gyroscope sense electrodes 127, 129, and y-axis accelerometer sense electrodes 131 can include moving fingers coupled to one or more proof-mass sections interdigitated with a set of stationary fingers fixed in position (e.g., to the via wafer 103) using a respective anchor, such as anchors 124, 126, 128, 130, 132.

Gyroscope Operational Modes

[0025] FIG. 3 illustrates generally an example of a 6-axis inertial sensor 300 in drive motion. In an example, the drive electrodes 123 can include a set of moving fingers coupled to the main proof-mass section 115 interdigitated with a set of stationary fingers fixed in position using a first drive anchor 124 (e.g., a raised and electrically isolated portion of the via wafer 103). In an example, the stationary fingers can be configured to receive energy through the first drive anchor 124, and the interaction between the interdigitated moving and stationary fingers of the drive electrodes 123 can be configured to provide an angular force to the single proof-mass about the z-axis.

[0026] In the example of FIG. 3, the drive electrodes 123 are driven to rotate the single proof-mass about the z-axis while the central suspension 111 provides restoring torque with respect to the fixed anchor 106, causing the single proof-mass to oscillate torsionally, in-plane about the z-axis at a drive frequency dependent on the energy applied to the drive electrodes 123. In certain examples, the drive motion of the single proof-mass can be detected using the drive electrodes 123.

X-Axis Rate Response

[0027] FIG. 4 illustrates generally an example of a 6-axis inertial sensor 400 including a single proof-mass during sense motion in response to rotation about the x-axis, the single proof-mass including a main proof-mass section 115, x-axis proof-mass sections 116, 117, y-axis proof-mass sections 118, 119, and central suspension 111.

[0028] In the presence of an angular rate about the x-axis, and in conjunction with the drive motion of the 6-axis inertial sensor 400 described in the example of FIG. 3, Coriolis forces in opposite directions along the z-axis can be induced on the x-axis proof-mass sections 116, 117 because the velocity vectors are in opposite directions along the y-axis. Thus, the single proof-mass can be excited torsionally about the y-axis by flexing the central suspension 111. The sense response can be detected using out-of-plane x-axis gyroscope sense electrodes, e.g., formed in the via wafer 103 and using capacitive coupling of the x-axis proof-mass sections 116, 117 and the via wafer 103).

Y-Axis Rate Response

[0029] FIG. 5 illustrates generally an example of a 6-axis inertial sensor 500 including a single proof-mass during sense motion in response to rotation about the y-axis, the single proof-mass including a main proof-mass section 115, x-axis proof-mass sections 116, 117, y-axis proof-mass sections 118, 119, and central suspension 111.

[0030] In the presence of an angular rate about the y-axis, and in conjunction with the drive motion of the 6-axis inertial sensor 400 described in the example of FIG. 3, Coriolis forces in opposite directions along the z-axis can be induced on the y-axis proof-mass sections 118, 119 because the velocity vectors are in opposite directions along the x-axis. Thus, the single proof-mass can be excited torsionally about the x-axis by flexing the central suspension 111. The sense response can be detected using out-of-plane y-axis gyroscope sense electrodes, e.g., formed in the via wafer 103 and using capacitive coupling of the y-axis proof-mass sections 118, 119 the via wafer 103.

Z-Axis Rate Response

[0031] FIG. 6 illustrates generally an example of a 6-axis inertial sensor 600 including a single proof-mass during sense motion in response to rotation about the z-axis, the single proof-mass including a main proof-mass section, x-axis proof-mass sections 116, 117, y-axis proof-mass sections, central suspension, multi-function flexure bearings 120, and z-axis gyroscope anti-phase flexure bearings 121.

[0032] In the presence of an angular rate about the z-axis, and in conjunction with the drive motion of the 6-axis inertial sensor 400 described in the example of FIG. 3, Coriolis forces in opposite directions along the x-axis can be induced on the x-axis proof-mass sections 116, 117 because the velocity vectors are in opposite directions along the y-axis. Thus, the x-axis proof-mass sections 116, 117 can be excited linearly in opposite directions along the x-axis by flexing the multi-function flexure bearings 120 in the x-direction. Further, the z-axis gyroscope anti-phase flexure bearings 121 can be used to provide a linear anti-phase resonant mode of x-axis proof-mass sections 116, 117, which are directly driven by the anti-phase Coriolis forces. The sense response can be detected using in-plane parallel-plate sense electrodes, such as the z-axis gyroscope sense electrodes 127, 129 formed in the device layer 105.

Accelerometer Operational Modes

[0033] In an example, the accelerometer response modes can be primarily enabled by the multi-function flexure bearings 120 and the y-axis accelerometer flexure bearings 122. The multi-function flexure bearings 120 can allow the x-axis proof-mass sections 116, 117 to respond to x and z-axis accelerations as well as the gyroscope motion, and the y-axis accelerometer flexure bearings 122 can allow the y-axis proof-mass sections 118, 119 to respond to y-axis accelerations.

X-Axis Accelerometer Response

[0034] FIG. 7 illustrates generally an example of a 6-axis inertial sensor 700 including a single proof-mass during sense motion in response to acceleration about the x-axis, the single proof-mass including a main proof-mass section, x-axis proof-mass sections 116, 117, y-axis proof-mass sections, central suspension, multi-function flexure bearings 120, and z-axis gyroscope anti-phase flexure bearings 121.

[0035] In the presence of x-axis acceleration, the x-axis proof-mass sections 116, 117 can deflect in-phase along the x-direction. The multi-function flexure bearings 120 can allow the x-axis proof-mass sections 116, 117 to move in unison in the x-direction. During this motion, the z-axis gyroscope anti-phase flexure bearings 121 between the x-axis proof-mass sections 116, 117 may not deflect, resulting in a lower frequency than the z-axis gyroscope sense frequency. The sense response can be detected using in-plane parallel-plate sense electrodes, such as the x-axis accelerometer sense electrodes 125 formed in the device layer 105.

Y-Axis Accelerometer Response

[0036] FIG. 8 illustrates generally an example of a 6-axis inertial sensor 800 including a single proof-mass during sense motion in response to acceleration about the y-axis, the single proof-mass including a main proof-mass section, x-axis proof-mass sections, y-axis proof-mass sections 118, 119, central suspension, multi-function flexure bearings, z-axis gyroscope anti-phase flexure bearings, and y-axis accelerometer flexure bearings 122.

[0037] In the presence of y-axis acceleration, the y-axis proof-mass sections 118, 119 can deflect in-phase along the y-direction. The y-axis accelerometer flexure bearings 122 can allow the y-axis proof-mass sections 118, 119 to move in unison relative to the main proof-mass section. The sense response can be detected using in-plane parallel-plate sense electrodes, such as the y-axis accelerometer sense electrodes 131 formed in the device layer 105.

Z-Axis Accelerometer Response

[0038] FIG. 9 illustrates generally an example of a 6-axis inertial sensor 900 including a single proof-mass during sense motion in response to acceleration about the z-axis, the single proof-mass including a main proof-mass section, x-axis proof-mass sections 116, 117, y-axis proof-mass sections, central suspension, multi-function flexure bearings 120, and z-axis gyroscope anti-phase flexure bearings 121.

[0039] In the presence of z-axis acceleration, the x-axis proof-mass sections 116, 117 can deflect torsionally in opposite directions out-of-plane. The multi-function flexure bearings 120 can act as torsional hinges, and can allow the x-axis proof-mass sections 116, 117 to move about an axis at the center of the multi-function flexure bearings 120. Because the areas on opposite sides of the multi-function flexure bearings 120 move in opposite directions, a fully differential detection scheme can be achieved with only one layer of out-of-plane electrodes located in the via wafer 103.

Out-of-Plane Electrode Placement

[0040] FIG. 10 illustrates generally an example of a system 1000 including via wafer 103 electrode placement. In certain examples, one or more conductive portions of the via wafer 103, such as electrodes, isolated conductive regions, etc., can be used to detect capacitive coupling between portions of the 6-axis inertial sensor and the via wafer 103, and in turn, to detect x-axis angular rate using x-axis gyroscope sense electrodes 140, to detect y-axis angular rate using y-axis gyroscope sense electrodes 141, and to detect z-axis acceleration using z-axis accelerometer sense electrodes 142.

Drive and Detection Frequencies

[0041] In an example, the drive mode and the three gyroscope sense modes can be located in the 20kHz range. For open-loop operation, the drive mode can be separated from the sense-modes by a mode separation, such as 100Hz to 500Hz, which can determine the mechanical sensitivity of the gyroscopes. To increase sensitivity, the gyroscope operational resonant frequencies can be reduced if the vibration specifications of the application allow. If closed-loop sense operation is implemented, the mode separation can be reduced to increase mechanical sensitivity further.

[0042] The accelerometer sense mode resonant frequencies can be located substantially below the gyroscope operational modes, for example, in the 5kHz to 10kHz range. Thus, the gyroscope and accelerometer signals can be separated in the frequency domain as well. Further, lower resonant frequencies can be implemented to increase sensitivity.

Curved In-Plane Parallel-Plate Electrodes

[0043] FIG. 11 illustrates generally an example of a 6-axis inertial sensor 1100 including a single proof-mass, the single proof-mass including a main proof-mass section 115, x-axis proof-mass sections 116, 117, and y-axis proof-mass sections 118, 119. In an example, one or more of the x-axis accelerometer sense electrodes 125, the z-axis gyroscope sense electrodes 127, or the y-axis accelerometer sense electrodes 131 can include curved in-plane parallel-plate electrodes, in certain examples, curved normal to the direction of the torsional drive motion to reduce the sensitivity of detection electrode capacitances to the gyroscope drive motion. Since the drive motion is rotational about the z-axis, the array of curved electrodes normal to the drive motion with centers at the die center would reduce the gap change or overlap area change due to the gyroscope drive motion.

Quadrature Error Reduction

[0044] FIG. 12 illustrates generally an example of the central suspension 111 at rest about an anchor 106, the central suspension 111 including symmetric "C-beams" configured to locally cancel quadrature error. The primary source of quadrature error in micromachined gyroscopes is the DRIE sidewall angle errors, which result in deviation of the etch profile from a straight sidewall. If sidewalls have an angle error, the in-plane drive motion can also cause out-of-plane motion when the skew axis is along beam length. Thus, when skewed compliant beams are located on opposite sides of the drive motion, the resulting out-of-plane deflections cause quadrature error.

[0045] FIG. 13 illustrates generally an example of a portion of the central suspension 111 in drive motion. The central suspension 111 utilizes symmetric "C-beams" on each side of the anchor 106. The out-of-plane motion caused by each C-beam on a side is cancelled out by its symmetric counterpart. Thus, the quadrature error induced on each beam can be locally cancelled.

Cross-Axis Sensitivity

[0046] The operational modes of the gyroscope and the accelerometer functions are very well decoupled by the suspension system, including the central suspension 111 and the multi-function flexure bearings 120, which effectively conserve the orthogonality of the operational modes. Thus, sense electrodes of each axis remain stationary with respect to the response motion in other axes. Furthermore, the gyroscope and accelerometer response signals are separated in the frequency domain, as described above.

Additional Notes and Examples

[0047] In Example 1, a 6-degrees-of-freedom (6-DOF) inertial measurement system includes a device layer including a single proof-mass 6-axis inertial sensor formed in an x-y plane, the single proof-mass 6-axis inertial sensor including a main proof-mass section suspended about a single, central anchor, the main proof-mass section including a radial portion extending outward towards the edge of the 6-axis inertial sensor, a central suspension system configured to suspend the 6-axis inertial sensor from the single, central anchor, and a drive electrode including a moving portion and a stationary portion, the moving portion coupled to the radial portion, wherein the drive electrode and the central suspension system are configured to oscillate the 6-axis inertial sensor about a z-axis normal to the x-y plane at a drive frequency. The single proof-mass 6-axis inertial sensor optionally includes a cap wafer bonded to a first surface of the device layer and a via wafer bonded to a second surface of the device layer, wherein the cap wafer and the via wafer are configured to encapsulate the single proof-mass 6-axis inertial sensor.

[0048] In Example 2, the single proof-mass 6-axis inertial sensor of Example 1 optionally includes first and second x-axis proof-mass sections coupled to the main proof-mass section using multi-function flexure bearings.

[0049] In Example 3, the multi-function flexure bearings of any one or more of Examples 1-2 are optionally configured to allow the first and second x-axis proof-mass sections to move in-phase or anti-phase along the x-axis.

[0050] In Example 4, the multi-function flexure bearings of any one or more of Examples 1-3 are optionally configured to allow the first and second x-axis proof-mass sections to move in-phase along the x-axis in response to an x-axis acceleration.

[0051] In Example 5, the multi-function flexure bearings of any one or more of Examples 1-4 are optionally configured to allow the first and second x-axis proof-mass sections to move anti-phase along the x-axis in response to a z-axis rotation.

[0052] In Example 6, the multi-function flexure bearings of any one or more of Examples 1-5 are optionally configured to allow each of the first and second x-axis proof-mass sections to rotate about the y-axis in response to a z-axis acceleration.

[0053] In Example 7, at least one of the multi-function flexure bearings of any one or more of Examples 1-6 is optionally elongate, extending between the main proof-mass section and the first x-axis proof-mass section along the y-axis.

[0054] In Example 8, the at least one multi-function flexure bearing of any one or more of Examples 1-7 is optionally configured to be flexed under torsion about an axis parallel to the y-axis.

[0055] In Example 9, four multi-function flexure bearings are optionally configured to couple the single proof-mass to the first and second x-axis proof-mass section, wherein for each multi-function flexure bearing there is an opposing multi-function bearing mirrored about the x-z plane, and another multi-function bearing mirrored about the y-z plane.

[0056] In Example 10, the first and second x-axis proof-mass sections of any one or more of Examples 1-9 are optionally coupled by an anti-phase flexure bearing that is elongate extending along the y-axis.

[0057] In Example 11, two anti-phase flexure bearings of any one or more of Examples 1-110 optionally couple the first x-axis proof-mass to the second x-axis proof-mass on opposing sides of the x-z plane.

[0058] In Example 12, each of the two anti-phase flexure bearings of any one or more of Examples 1-11 zigzag as they extend along the x-axis between the first and second x-axis proof-masses.

[0059] In Example 13, the single proof-mass of any one or more of Examples 1-12 is optionally quadrilateral in shape, wherein the single, central anchor is centered in the quadrilateral, and wherein the main proof-mass section includes four radial portions extending outward towards the four corners of the 6-axis inertial sensor.

[0060] In Example 14, the drive electrode of any one or more of Examples 1-13 optionally includes a plurality of moving fingers interdigitated with a plurality of stationary fingers, and wherein the stationary fingers are anchored to the via wafer.

[0061] In Example 15, any one or more of Examples 1-12 optionally includes first electrodes in-plane with the device layer and configured to detect z-axis angular rotation, x-axis acceleration, and y-axis acceleration and second electrodes out-of-plane with the device layer and configured to detect z-axis acceleration, x-axis angular rotation, and y-axis angular rotation.

[0062] In Example 16, the via wafer of any one or more of Examples 1-15 optionally includes the second electrodes, and the second electrodes are optionally capacitively coupled to the device layer.

[0063] In Example 17, a single proof-mass, micromachined, monolithic, 6-axis inertial sensor apparatus includes a main proof-mass section suspended about a single, central anchor, the main proof-mass section including radial portions extending outward towards the edge of the 6-axis inertial sensor, a pair of x-axis proof-mass sections coupled to the main proof-mass section using multi-function flexure bearings and coupled to each other using an anti-phase flexure bearing; a pair of y-axis proof-mass sections coupled to multiple radial portions of the main proof-mass section using elongated flexure bearings, a central suspension system configured to suspend the 6-axis inertial sensor from the single, central anchor; and a drive electrode including a moving portion and a stationary portion, the moving portion coupled to the radial portion, wherein the drive electrode and the central suspension system are configured to oscillate the 6-axis inertial sensor about a z-axis normal to the x-y plane at a drive frequency.

[0064] In Example 18, the multi-function flexure bearings of any one or more of Examples 1-17 are optionally configured to allow the first and second x-axis proof-mass sections to move in-phase or anti-phase along the x-axis.

[0065] In Example 19, the multi-function flexure bearings of any one or more of Examples 1-18 are optionally configured to allow the first and second x-axis proof-mass sections to move in-phase along the x-axis in response to an x-axis acceleration, and anti-phase along the x-axis in response to a z-axis rotation.

[0066] In Example 20, the multi-function flexure bearings of any one or more of Examples 1-19 are optionally configured to allow each of the first and second x-axis proof-mass sections to rotate about the y-axis in response to a z-axis acceleration.

[0067] In Example 21, a method includes suspending a single proof-mass of a 6-axis inertial sensor about a single, central anchor coupled to a stationary layer using central suspension, the main proof-mass section including a radial portion extending outward towards the edge of the 6-axis inertial sensor, suspending first and second x-axis proof-mass sections from the main proof-mass section using multi-function flexure bearings, anchoring a stationary drive electrode to the stationary layer, coupling a moveable electrode to the stationary electrode, and oscillating the single proof-mass at a drive frequency using the stationary drive electrode, the moveable electrode, and the central suspension.

[0068] In Example 22, a system or apparatus can include, or can optionally be combined with any portion or combination of any portions of any one or more of Examples 1-21 to include, means for performing any one or more of the functions of Examples 1-21, or a machine-readable medium including instructions that, when performed by a machine, cause the machine to perform any one or more of the functions of Examples 1-20.

[0069] The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific comparative examples in which the invention can be practiced.

[0070] In this document, the terms "a" or "an" are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of "at least one" or "one or more." In this document, the term "or" is used to refer to a nonexclusive or, such that "A or B" includes "A but not B," "B but not A," and "A and B," unless otherwise indicated. In the appended claims, the terms "including" and "in which" are used as the plain-English equivalents
of the respective terms "comprising" and "wherein." Also, in the following claims, the terms "including" and "comprising" are open-ended, that is, a system, device, article, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms "first," "second," and "third," etc. are used merely as labels, and are not intended to impose numerical requirements on their objects.

[0071] The above description is intended to be illustrative, and not restrictive. In other examples, the above-described examples (or one or more aspects thereof) may be used in combination with each other. Other comparative examples can be used, such as by one of ordinary skill in the art upon reviewing the above description. The Abstract is provided to to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter may lie in less than all features of a particular disclosed comparative example. The scope of the invention should be determined with reference to the appended claims.

Claims

1. A single proof-mass, micromachined, monolithic, 6-axis inertial sensor apparatus (200), comprising:

a main proof-mass section (115) forming an x-y plane suspended about a single, central anchor (106) coupled to a stationary layer (103), the main proof-mass section including radial portions extending outward towards the edge of the 6-axis inertial sensor;

a pair of first and second x-axis proof-mass sections (116, 117) coupled to the main proof-mass section using multi-function flexure bearings (120), the multi-function flexure bearings (120) configured to allow the first and second x-axis proof-mass sections to move in-phase or anti-phase along the x-axis of the x-y plane, and coupled to each other using an anti-phase flexure bearing (121);

a pair of y-axis proof-mass sections (118, 119) coupled to multiple radial portions of the main proof-mass section using elongated flexure bearings (122);

a central suspension system configured to suspend the 6-axis inertial sensor from the single, central anchor; and

a drive electrode (123) including a moving portion and a stationary portion, the moving portion coupled to the radial portion and the stationary portion anchored to the stationary layer (103) wherein the drive electrode and the central suspension system are configured to oscillate the 6-axis inertial sensor about a z-axis normal to the x-y plane at a drive frequency.

2. The apparatus (200) of claim 1 wherein the multi-function flexure bearings (120) are configured to allow each of the first and second x-axis proof-mass sections (116, 117) to rotate about the y-axis in response to a z-axis acceleration, and/or wherein at least one of the multi-function flexure bearings is elongate, extending between the main proof-mass section (115) and the first x-axis proof-mass section (116) along the y-axis.

3. The apparatus (200) of claim 1, wherein the multi-function flexure bearings (120) are configured to allow the first and second x-axis proof-mass sections (116, 117) to move in-phase along the x-axis in response to an x-axis acceleration, and anti-phase along the x-axis in response to a z-axis rotation.

4. The apparatus (200) of claim 3, wherein the multi-function flexure bearings (120) include first, second, third and fourth multi-function flexure bearings to couple the single proof-mass to the first and second x-axis proof-mass section, wherein for each multi-function flexure bearing there is an opposing multi-function bearing mirrored about an x-z plane, and another multi-function bearing mirrored about an y-z plane, wherein the at least one multi-function flexure bearing is configured to be flexed under torsion about an axis parallel to the y-axis.

5. The apparatus (200) of claim 1, wherein the anti-phase flexure bearing (121) is elongate extending along the y-axis.

6. The apparatus (200) of claim 5, wherein the anti-phase flexure bearing (121) includes first and second anti-phase flexure bearings coupling the pair of x-axis proof-mass sections (116, 117) on opposing sides of an x-z plane.

7. The apparatus (200) of claim 6, wherein each of the two anti-phase flexure bearings zigzag as they extend along the x-axis between the first and second x-axis proof-masses.

8. The apparatus (200) of claim 1, wherein the single proof-mass is quadrilateral in shape, wherein the single, central anchor (106) is centered in the quadrilateral, and wherein the main proof-mass section (115) includes four radial portions extending outward towards the four corners of the 6-axis inertial sensor, and/or wherein the drive electrode (123) includes a plurality of moving fingers interdigitated with a plurality of stationary fingers, and wherein the stationary fingers are anchored to a via wafer (103).

9. The apparatus (200) of claim 1, including:

first electrodes (125, 127, 129 131) in-plane with the x-y plane and configured to detect z-axis angular rotation, x-axis acceleration, and y-axis acceleration; and

second electrodes (140, 141, 142) out-of-plane with the x-y plane and configured to detect z-axis acceleration, x-axis angular rotation, and y-axis angular rotation.

10. A method, comprising:

suspending a single proof-mass of a 6-axis inertial sensor (200) about a single, central anchor (106) coupled to a stationary layer (103) using central suspension, the single proof-mass comprising a main proof-mass section (115) forming an x-y plane and including radial portions extending outward towards the edge of the 6-axis inertial sensor;

coupling a pair of a first and second x-axis proof-mass sections to the main proof-mass section using multi-function flexure bearings configured to allow the first and second x-axis proof-mass sections to move in-phase or anti-phase along the x-axis of an x-y plane, and to each other using an anti-phase flexure bearing (121);

coupling a pair of y-axis proof-mass sections (118, 119) to multiple radial portions of the main proof-mass section using elongated flexure bearings;

anchoring a stationary drive electrode portion (123) to the stationary layer (103);

coupling a moveable electrode portion (123) to the radial portion;

oscillating the single proof-mass about a z-axis normal to the x-y plane at a drive frequency using the stationary drive electrode portion (123), the moveable electrode portion (123), and the central suspension.

11. The method of claim 10, wherein the multi-function flexure bearings (120) are configured to allow the first and second x-axis proof-mass sections (116, 117) to move in-phase along the x-axis in response to an x-axis acceleration, anti-phase along the x-axis in response to a z-axis rotation, and to rotate about the y-axis in response to a z-axis acceleration.

Ansprüche

1. Mikrobearbeitete, monolithische 6-Achsen-Trägheitssensorvorrichtung (200) mit einer einzelnen Probemasse, aufweisend:

einen Hauptprobemassenabschnitt (115), der eine x-y-Ebene bildet, die um einen mit einer stationären Schicht (103) gekoppelten einzelnen zentralen Anker (106) aufgehängt ist, wobei der Hauptprobemassenabschnitt radiale Teilabschnitte enthält, die sich nach außen zum Rand des 6-Achsen-Trägheitssensors erstrecken;

ein Paar erste und zweite x-Achsen-Probemassenabschnitte (116, 117), die mit dem Hauptprobemassenabschnitt mittels Multifunktions-Biegescharnieren (120) gekoppelt sind, wobei die Multifunktions-Biegescharniere (120) so konfiguriert sind, dass sie eine phasengleiche oder gegenphasige Bewegung des ersten und des zweiten x-Achsen-Probemassenabschnitts entlang der x-Achse der x-y-Ebene ermöglichen, und die miteinander mittels eines gegenphasigen Multifunktions-Biegescharniere (121) gekoppelt sind;

ein Paar y-Achsen-Probemassenabschnitte (118, 119), die mit mehreren radialen Abschnitten des Hauptprobemassenabschnitts mittels länglicher Biegescharniere (122) gekoppelt sind;

ein zentrales Aufhängungssystem, das zur Aufhängung des 6-Achsen-Trägheitssensors an einem einzelnen zentralen Anker konfiguriert ist; und

eine Antriebselektrode (123) mit einem beweglichen Abschnitt und einem stationären Abschnitt, wobei der bewegliche Abschnitt mit dem radialen Abschnitt gekoppelt und der stationäre Abschnitt an der stationären Schicht (103) verankert ist,

wobei die Antriebselektrode und das zentrale Aufhängungssystem dazu konfiguriert sind, den 6-Achsen-Trägheitssensor um die z-Achse senkrecht zur x-y-Ebene mit einer Antriebsfrequenz in Schwingung zu versetzen.

2. Vorrichtung (200) nach Anspruch 1, wobei die Multifunktions-Biegescharniere (120) so konfiguriert sind, dass sie sowohl dem ersten als auch dem zweiten x-Achsen-Probemassenabschnitt (116, 117) gestatten, sich als Reaktion auf eine z-Achsenbeschleunigung um die y-Achse zu drehen, und/oder wobei mindestens eines der Multifunktions-Biegescharniere länglich ist und sich zwischen dem Hauptprobemassenabschnitt (115) und dem ersten x-Achsen-Probemassenabschnitt (116) entlang der y-Achse erstreckt.

3. Vorrichtung (200) nach Anspruch 1, wobei die Multifunktions-Biegescharniere (120) so konfiguriert sind, dass sie dem ersten und dem zweiten x-Achsen-Probemassenabschnitt (116, 117) gestatten, sich phasengleich entlang der x-Achse als Reaktion auf eine x-Achsenbeschleunigung und gegenphasig entlang der x-Achse als Reaktion auf eine z-Achsenrotation zu bewegen.

4. Vorrichtung (200) nach Anspruch 3, wobei die Multifunktions-Biegescharniere (120) erste, zweite, dritte und vierte Multifunktions-Biegescharniere aufweisen, um die einzelne Probemasse mit einem ersten und einem zweiten x-Achsen-Probemassenabschnitt zu koppeln, wobei für jedes Multifunktions-Biegescharnier ein um eine x-z-Ebene gespiegeltes gegenüberliegendes Multifunktions-Biegescharnier und ein weiteres um eine y-z-Ebene gespiegeltes Multifunktions-Biegescharnier vorgesehen sind, wobei das mindestens eine Multifunktions-Biegescharnier so konfiguriert ist, dass es sich unter Zugkraft um eine Ache parallel zur y-Achse biegt.

5. Vorrichtung (200) nach Anspruch 1, wobei das gegenphasige Biegescharnier (121) länglich ist und sich entlang der y-Achse erstreckt.

6. Vorrichtung (200) nach Anspruch 5, wobei das gegenphasige Biegescharnier (121) ein erstes und ein zweites gegenphasiges Biegescharnier aufweist, das das Paar erste und zweite x-Achsen-Probemassenabschnitte (116, 117) an gegenüberliegenden Seiten einer x-z-Ebene koppelt.

7. Vorrichtung (200) nach Anspruch 6, wobei jedes der zwei gegenphasigen Biegescharniere eine Zick-Zick-Form annimmt, während sie sich entlang der x-Achse zwischen der ersten und der zweiten x-Achsen-Probemasse erstrecken.

8. Vorrichtung (200) nach Anspruch 1, wobei die einzelne Probemasse eine Viereckform hat, wobei der einzelne zentrale Anker (106) im Viereck zentriert ist, und wobei der Hauptprobemassenabschnitt (115) vier radiale Abschnitte hat, die sich nach außen zu den vier Ecken des 6-Achsen-Trägheitssensors erstrecken, und/oder wobei die Antriebselektrode (123) eine Mehrzahl beweglicher Finger aufweist, die mit einer Mehrzahl stationärer Finger verschränkt sind, und wobei die stationären Finger an einem Verbindungsloch-Wafer (103) verankert sind.

9. Vorrichtung (200) nach Anspruch 1, mit:

ersten Elektroden (125, 127, 129, 131), die in der x-y-Ebene liegen und zum Detektieren der Winkelrotation der z-Achse, der Beschleunigung der x-Achse und der Beschleunigung der y-Achse konfiguriert sind; und

zweiten Elektroden (140, 141, 142), die außerhalb der x-y-Ebene liegen, und zum Detektieren der Beschleunigung der z-Achse, der Winkelrotation der x-Achse und der der Winkelrotation der y-Achse konfiguriert sind.

10. Verfahren, aufweisend:

Aufhängen einer einzelnen Probemasse eines 6-Achsen-Trägheitssensors (200) um einen einzelnen zentralen Anker (106), der mit einer stationären Schicht (103) gekoppelt ist, mittels einer zentralen Aufhängung, wobei die einzelne Probemasse einen Hauptprobemassenabschnitt (115) aufweist, der eine x-y-Ebene bildet und radiale Abschnitte hat, die sich nach außen zum Rand des 6-Achsen-Trägheitssensors erstrecken;

Koppeln eines Paares erster und zweiter x-Achsen-Probemassenabschnitte mit dem Hauptprobemassenabschnitt mittels Multifunktions-Biegescharnieren, die so konfiguriert sind, dass sie eine phasengleiche oder gegenphasige Bewegung des ersten und des zweiten x-Achsen-Probemassenabschnitts entlang der x-Achse der x-y-Ebene und zueinander mittels eines gegenphasige Biegescharnier (121) ermöglichen;

Koppeln eines Paares y-Achsen-Probemassenabschnitte (118, 119) mit mehreren radialen Abschnitten des Hauptprobemassenabschnitts mittels länglicher Biegescharniere;

Verankern eines stationären Antriebselektrodenabschnitts (123) an der stationären Schicht (103);

Koppeln eines beweglichen Elektrodenabschnitts (123) mit dem radialen Abschnitt;

in Schwingung versetzen der einzelnen Probemasse um die z-Achse senkrecht zur x-y-Ebene mit einer Antriebsfrequenz mittels des stationären Abschnitts der Antriebselektrode (123) und der zentralen Aufhängung.

11. Verfahren nach Anspruch 10, wobei die Multifunktions-Biegescharniere (120) konfiguriert sind, dem ersten und dem zweiten x-Achsen-Probemassenabschnitt (116, 117) zu gestatten, sich phasengleich entlang der x-Achse als Reaktion auf eine x-Achsenbeschleunigung, gegenphasig entlang der x-Achse als Reaktion auf eine z-Achsenbeschleunigung zu bewegen und sich als Reaktion auf eine z-Achsenbeschleunigung zu drehen.

Revendications

1. Appareil (200) à capteur inertiel 6 axes monolithique micro-usiné à masse d'épreuve unique, comprenant :

une section de masse d'épreuve principale (115) formant un plan x-y suspendue autour d'un ancrage central unique (106) couplé à une couche stationnaire (103), la section de masse d'épreuve principale incluant des parties radiales s'étendant vers l'extérieur vers le bord du capteur inertiel 6 axes ;

une paire de première et deuxième sections de masse d'épreuve d'axe x (116, 117) couplées à la section de masse d'épreuve principale en utilisant des paliers à flexion multifonctions (120), les paliers à flexion multifonctions (120) configurés pour permettre que les première et deuxième sections de masse d'épreuve d'axe x se déplacent en phase ou en opposition de phase le long de l'axe x du plan x-y, et couplées l'une à l'autre en utilisant un palier à flexion en opposition de phase (121) ;

une paire de sections de masse d'épreuve d'axe y (118, 119) couplées à des parties radiales multiples de la section de masse d'épreuve principale en utilisant des paliers à flexion allongés (122) ;

un système de suspension centrale configuré pour suspendre le capteur inertiel 6 axes à l'ancrage central unique ; et

une électrode de commande (123) incluant une partie mobile et une partie stationnaire, la partie mobile couplée à la partie radiale et la partie stationnaire ancrée sur la couche stationnaire (103), dans lequel l'électrode de commande et le système de suspension centrale sont configurés pour faire osciller le capteur inertiel 6 axes autour d'un axe z normal au plan x-y à une fréquence de commande.

2. Appareil (200) selon la revendication 1, dans lequel les paliers à flexion multifonctions (120) sont configurés pour permettre que chacune des première et deuxième sections de masse d'épreuve d'axe x (116, 117) tourne autour de l'axe y en réponse à une accélération d'axe z, et/ou dans lequel au moins un des paliers à flexion multifonctions est allongé, s'étendant entre la section de masse d'épreuve principale (115) et la première section de masse d'épreuve d'axe x (116) le long de l'axe y.

3. Appareil (200) selon la revendication 1, dans lequel les paliers à flexion multifonctions (120) sont configurés pour permettre que les première et deuxième sections de masse d'épreuve d'axe x (116, 117) se déplacent en phase le long de l'axe x en réponse à une accélération d'axe x, et en opposition de phase le long de l'axe x en réponse à une rotation d'axe z.

4. Appareil (200) selon la revendication 3, dans lequel les paliers à flexion multifonctions (120) incluent des premier, deuxième, troisième et quatrième paliers à flexion multifonctions pour coupler la masse d'épreuve unique à la première et la deuxième section de masse d'épreuve d'axe x, dans lequel pour chaque palier à flexion multifonctions il y a un palier multifonctions opposé en miroir autour d'un plan x-z, et un autre palier multifonctions en miroir autour d'un plan y-z, dans lequel l'au moins un palier à flexion multifonctions est configuré pour être fléchi sous torsion autour d'un axe parallèle à l'axe y.

5. Appareil (200) selon la revendication 1, dans lequel le palier à flexion en opposition de phase (121) est allongé s'étendant le long de l'axe y.

6. Appareil (200) selon la revendication 5, dans lequel le palier à flexion en opposition de phase (121) inclut des premier et deuxième paliers à flexion en opposition de phase couplant la paire de sections de masse d'épreuve d'axe x (116, 117) sur des côtés opposés d'un plan x-z.

7. Appareil (200) selon la revendication 6, dans lequel chacun des deux paliers à flexion en opposition de phase zigzague alors qu'il s'étend le long de l'axe x entre les première et deuxième masses d'épreuve d'axe x.

8. Appareil (200) selon la revendication 1, dans lequel la masse d'épreuve unique est quadrilatérale de forme, dans lequel l'ancrage central unique (106) est centré dans le quadrilatère, et dans lequel la section de masse d'épreuve principale (115) inclut quatre parties radiales s'étendant vers l'extérieur vers les quatre angles du capteur inertiel 6 axes, et/ou dans lequel l'électrode de commande (123) inclut une pluralité de doigts mobiles interdigités avec une pluralité de doigts stationnaires, et dans lequel les doigts stationnaires sont ancrés sur une plaquette de connexion (103).

9. Appareil (200) selon la revendication 1, incluant :

des premières électrodes (125, 127, 129, 131) dans le plan avec le plan x-y et configurées pour détecter une rotation angulaire d'axe z, une accélération d'axe x, et une accélération d'axe y ; et

des deuxièmes électrodes (140, 141, 142) hors du plan avec le plan x-y et configurées pour détecter une accélération d'axe z, une rotation angulaire d'axe x, et une rotation angulaire d'axe y.

10. Procédé, comprenant :

la suspension d'une masse d'épreuve unique d'un capteur inertiel 6 axes (200) autour d'un ancrage central unique (106) couplé à une couche stationnaire (103) en utilisant une suspension centrale, la masse d'épreuve unique comprenant une section de masse d'épreuve principale (115) formant un plan x-y et incluant des parties radiales s'étendant vers l'extérieur vers le bord du capteur inertiel 6 axes ;

le couplage d'une paire de première et deuxième sections de masse d'épreuve d'axe x à la section de masse d'épreuve principale en utilisant des paliers à flexion multifonctions configurés pour permettre que les première et deuxième sections de masse d'épreuve d'axe x se déplacent en phase ou en opposition de phase le long de l'axe x d'un plan x-y, et l'une à l'autre en utilisant un palier à flexion en opposition de phase (121) ;

le couplage d'une paire de sections de masse d'épreuve d'axe y (118, 119) à des parties radiales multiples de la section de masse d'épreuve principale en utilisant des paliers à flexion allongés ;

l'ancrage d'une partie stationnaire d'électrode de commande (123) sur la couche stationnaire (103) ;

le couplage d'une partie mobile d'électrode (123) à la partie radiale ;

l'oscillation de la masse d'épreuve unique autour d'un axe z normal au plan x-y à une fréquence de commande en utilisant la partie stationnaire d'électrode de commande (123), la partie mobile d'électrode (123), et la suspension centrale.

11. Procédé selon la revendication 10, dans lequel les paliers à flexion multifonctions (120) sont configurés pour permettre que les première et deuxième sections de masse d'épreuve d'axe x (116, 117) se déplacent en phase le long de l'axe x en réponse à une accélération d'axe x, en opposition de phase le long de l'axe x en réponse à une rotation d'axe z, et tournent autour de l'axe y en réponse à une accélération d'axe z.

Drawing